Async persist connection control

redis-async-connection.c

//
//  main.c
//  redisd
//
//  Created by Cube on 15/8/19.
//  Copyright (c) 2015年 cube. All rights reserved.
//

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>

#include <event2/event.h>
#include <hiredis/hiredis.h>
#include <hiredis/async.h>
#include <hiredis/adapters/libevent.h>

struct Ctx {
  int freed;
  struct event_base * eb;
  redisAsyncContext * ac;
};

void rds_cb(struct redisAsyncContext * ac, void * reply, void * ptr)
{
  redisReply * r = reply;
  
  if (ac->err) {
    // printf("redis: %s %s\n", __FUNCTION__, ac->errstr);
  } else if (!r) {
    printf("reply: NULL\n");
  } else if (r->type == REDIS_REPLY_ERROR) {
    printf("reply: %s\n", r->str);
  } else {
    // everything is ok
  }
}

void rds_ifree_cb(const struct redisAsyncContext * ac, int err)
{
  struct Ctx * ctx = ac->data;
  if (err) {
    ctx->freed = 1;
    printf("redis: freed: %s\n", ac->errstr);
  }
}

void rds_connect(struct Ctx * ctx)
{
  if (!ctx->freed) return;
  // do connect
  ctx->ac       = redisAsyncConnect("192.168.44.67", 6379);
  ctx->ac->data = ctx;
  ctx->freed    = 0;
  redisAsyncSetConnectCallback   (ctx->ac, rds_ifree_cb);
  redisAsyncSetDisconnectCallback(ctx->ac, rds_ifree_cb);
  redisLibeventAttach            (ctx->ac, ctx->eb);
}

void evt_cb(int fd, short which, void * ptr)
{
  struct Ctx * ctx = ptr;
  // do connect
  rds_connect(ctx);
  // do send command
  redisAsyncCommand(ctx->ac, rds_cb, ctx, "set %s %d", "hello", 123);
}

int main(int argc, const char * argv[])
{
  signal(SIGPIPE, SIG_IGN);
  
  struct Ctx * ctx = malloc(sizeof(struct Ctx));
  
  ctx->eb    = event_base_new();
  ctx->ac    = NULL;
  ctx->freed = 1;
  
  struct timeval tv = {0, 100};
  struct event * e = event_new(ctx->eb, -1, EV_PERSIST | EV_TIMEOUT, evt_cb, ctx);
  
  event_add(e, &tv);
  event_base_loop(ctx->eb, 0);
}